Conclusion

From the hypothetical demons that troubled Martín del Rio to Isaac Newton’s theory of universal gravitation, the seventeenth century was marked by a steady preoccupation with the unseen. European naturalists wrestled with how to make sense of a universe that seemed to grow more uncertain all the time, even as technologies such as the telescope and microscope continued to reveal how little of that universe they actually saw. Given how central the unseen was to this period, it is unsurprising that the “new philosophies” of nature, those progenitors of modern science, actually embraced occult qualities and powers wholeheartedly, integrating the unseen into their very foundations. ¹ This dependence on occult causes might be explained by the fact that, after the middle of the seventeenth century, many natural philosophers were “post-skeptics,” the self-conscious beneficiaries of the previous century’s struggles with skepticism and consequently reconciled to a study of nature based on probability rather than on certainty. ² Thus, as thinkers became more comfortable with world systems that did not require demonstrative or empirical certainty, they also became more willing to invoke invisible causes to explain natural effects.